You don't need to actually fall asleep for a nap to be beneficial. I like to lay on the floor, feet up, and alarm set. 10-15 minutes and I feel completely refreshed.
This isn't a replacement for actual sleep, but I've never been a napper and the above I found super useful for me.
I second that, even closing the eyes for 10–15 min feels refreshing. Learned that when our kid was younger.
I literally described how I achieve it. I don't "try to fall asleep", that never works.